The present invention relates to a cam system for flat-bed knitting machines provided with a knitting carriage running in one direction, on which the loop transfer cam system and the knitting needles, insertable in the needle bed and provided with expanding springs for the loop transfer without racking of the needle bed, are arranged. The cam system can be modified so as to be applied to the flat-bed knitting machines with carriages movable back and forth and to the circular knitting machines with the rotatable cam cylinder.
It has been known that in the flat-bed knitting machines having knitting carriages running in one direction, the knitting and the loop transfer have been realized by means of an integrated cam system. Thereby the switchable cam is connected to the guide cams for the separation of the needle paths for the loop transfer and the loop acceptance and knitting motion, and an adjustable loop transfer cam and a tuck cam are arranged so that a upper needle clearing cam is connected thereto. A switchable cam is positioned opposite to the upper needle for releasing the knitting needles for the loop transfer or the loop formation, the tuck loop formation and the loop acceptance. Further guide cams and a needle spring cam are connected to a combing element. A needle-selecting system is integrated with the cam system. The cam system further has at the level of guide cams a sinker selection arrangement and a pressure bar or override system. The tuck cam also serves as a loop accepting cam.
The disadvantage of this conventional cam system resides in that, during the loop transfer the knitting can not be performed simultaneously, and it is impossible, in order to obtain certain pattern effect, to press individual loops during the knitting as well as to obtain the loops of larger size in the same knitting row.
A cam system for a knitting machine has been disclosed in DE-OS No. 2,304,651. The cam track in this system is arranged after the upper needle clearing cam and before the cam for pulling off the needle. The knitting needles containing no threads are pulled off by that needle spring-cam. The knitting needles are connected with a push rod cam. The pulling off of the knitting needles over the cam track is guided by the push rod cam or by the side picker.
As understood this cam system does not provide for the transfer of the loops to the opposite needle bed, whereby a new pattern effect can not be achieved.